Here's one tip that may be helpful as you prepare to cut information in your presentation. Since you are great at speaking on a topic with no notes, one way to capture the structure of the talk with still being spontaneous is the use of post-it notes.

Below is an example of a presentation I did a couple of years ago. The large orange notes are the main sections of the presentation. The small yellow notes are supporting points. You’ll notice that I structured my talk by contrasting what is and to what could be as I learned from Nancy Duarte. ​

There is no one way to go about a TED talk. It’s about finding what works best for your speaking style and message.